I think that's exactly the problem. The polls I saw here in Europe showed indeed a small margin for Clinton. It was however the analysis and commentary of these poll results that was way out of wack. Normally one would have expected that "objective" pollsters would have called it "too close to call", but they didn't. Their analysis and commentary was too much skewed by "wishful thinking". Even looking at the raw results I as a layman in statistics didn't understand why they had such high confidence in Clinton winning on such a small margin (and small sample size). Let's hope they have learned from this, but I'm not holding my breath.
First off, Presidents don't win elections by the popular vote. It's the electoral vote that counts. That's why all those maps of the 50 states on TV where the pundits explained over and over again for months how there was no chance for Trump to win electorally was the main mistake. Trump actually won 306-232 electoral votes or 57%-43%. The way the experts had the electoral votes going, Hillary should have won 60%-40%.
Also, the so-called "minimal" 70,000 vote margin Trump had in the key states of Michigan, Wisconsin, and Pennsylvania, are deceiving. Clinton should have won those states by a million votes. So what happened was that over a million traditional Democrats switched sides in those three key states, not just the 70,000 the media keeps referring too. So the press should be talking about how 1,070,000 voters made the difference, not 70,000. But as usual, they're distorting the results by only talking about the 70,000 to make his win in those three states seem less impressive than it was.
In any case, if Clinton actually won those three states, the final electoral results would have been only 274 Clinton to 264 Trump or electorally 50.7% Clinton to 49.3% Trump, much, much less than her predicted landslide. She had been expected to win with 335 electoral votes or over 60% of the electoral vote. That means that she also didn't win many other states where she had been expected to do better.
Like you said, the commentary was "out of wack and wishful thinking".